Getting variables from loaded movies

I’ve created a global variable in the first frame of my main movie:

_global.gMyScore = 0;

I’m loading a smaller movie into a movie clip in the second frame of that movie, it understands the score from the main movie global variable.

The score is changing in that movie depending how a user answers questions (radio buttons):

if (true_btn.selected == true)
gMyScore = gMyScore+10;


This is working in that movie, but I want to pass it on to the main movie, to affect the score in subsequent loaded movies, and I can’t figure out how to do that (it’s on a next button handler that loads the next movie).
Any help would be greatly appreciated.